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<table width="100%" summary="page for intersalt"><tr><td>intersalt</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Blood pressure versus Salt; inter-population data</h2>

<h3>Description</h3>

<p>Median blood pressure, as a fuction of salt intake, for each of 52
human populations.
</p>


<h3>Usage</h3>

<pre>intersalt</pre>


<h3>Format</h3>

<p>A data frame with 52 observations on the following 4 variables.
</p>

<dl>
<dt><code>b</code></dt><dd><p>a numeric vector</p>
</dd>
<dt><code>bp</code></dt><dd><p>mean diastolic blood pressure (mm Hg)</p>
</dd>
<dt><code>na</code></dt><dd><p>mean sodium excretion (mmol/24h)</p>
</dd>
<dt><code>country</code></dt><dd><p>a character vector</p>
</dd>
</dl>



<h3>Details</h3>

<p>For each population took a sample of 25 males and 25 females from each
decade in the age range 20 - 50, i.e. 200 individuals in all.
</p>


<h3>Source</h3>

<p>Intersalt Cooperative Research Group. 1988.  Intersalt: an international
study of electrolyte excretion and blood pressure: results for 24 hour
urinary sodium and potassium excretion.  <em>British Medical Journal</em>
297: 319-328.  
</p>


<h3>References</h3>

<p>Maindonald, J.H. <em>The Design of Research Studies ? A Statistical
Perspective</em>, viii + 109pp. Graduate School Occasional Paper 00/2, 
Australian National University 2000.
</p>


<h3>Examples</h3>

<pre>
data(intersalt)
plot(bp ~ na, data=intersalt, xlab="Median sodium excretion (mmol/24h)",
     ylab="Median diatoluc blood pressure (mm Hg)")
</pre>


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